PEERLESS SERIES GM Instruction manual

GM
Boilers
Series
Gas
Installation,
Operation &
Maintenance
Manual

USING THIS MANUAL 1
A. INSTALLATION SEQUENCE . . . . . . . . . . . . .1
B. SPECIAL ATTENTION BOXES . . . . . . . . . . . .1
1. PREINSTALLATION 2
A. ACCESSIBILITY CLEARANCES . . . . . . . . . . .2
B. CLEARANCE FROM COMBUSTIBLE
CONSTRUCTION . . . . . . . . . . . . . . . . . . . . . .2
C. COMBUSTION AND VENTILATION AIR . . . .2
D. INSTALLATION SURVEY . . . . . . . . . . . . . . . .5
E. CIRCULATORS . . . . . . . . . . . . . . . . . . . . . . . .5
F. PLANNING THE LAYOUT . . . . . . . . . . . . . . . .5
2. BOILER SET-UP 6
3. WATER PIPING AND CONTROLS 7
A. BOILER SUPPLY AND RETURN . . . . . . . . . . .7
B. SAFETY RELIEF VALVE . . . . . . . . . . . . . . . . .8
C. PIPING FOR ZONED SYSTEMS . . . . . . . . . . .9
D. EXPANSION TANK . . . . . . . . . . . . . . . . . . . .10
E. INDIRECT-FIRED WATER HEATER . . . . . . .10
F. FREEZE PROTECTION . . . . . . . . . . . . . . . . .10
4. VENTING 11
A. DRAFT HOOD . . . . . . . . . . . . . . . . . . . . . . .11
B. AUTOMATIC VENT DAMPER
INSTALLATION – GENERAL . . . . . . . . . . . .12
C. VENT PIPING AND CHIMNEY . . . . . . . . . . .12
D. BOILER REMOVAL FROM COMMON
VENTING SYSTEM . . . . . . . . . . . . . . . . . . .13
5. GAS PIPING 14
6. ELECTRICAL 16
A. WIRING . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
B. CIRCULATOR/ZONE VALVE WIRING . . . . . .16
C. LOW WATER CUTOFF . . . . . . . . . . . . . . . . .16
7. CSD CODE REQUIREMENTS 23
A. GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . .23
B. CSD PART CF REQUIREMENTS . . . . . . . . .23
C. CSD PART CW REQUIREMENTS . . . . . . . .23
D. CSD MODULAR AND MULTIPLE BOILER
REQUIREMENTS . . . . . . . . . . . . . . . . . . . . .23
E. CSD PART CE ELECTRICAL
REQUIREMENTS . . . . . . . . . . . . . . . . . . . . .24
8. START-UP PROCEDURES 25
A. COMPLETING THE INSTALLATION . . . . . . .25
B. CONTROL DESCRIPTIONS . . . . . . . . . . . . .30
C. ADJUSTMENT OF GAS PRESSURE
REGULATOR . . . . . . . . . . . . . . . . . . . . . . . . .30
D. CHECKING BURNER INPUT . . . . . . . . . . . . .30
E. CHECK-OUT PROCEDURE . . . . . . . . . . . . . .31
9. TROUBLESHOOTING 32
A. SHUT-DOWN CAUSED BY PILOT OUTAGE,
VENT SAFETY SHUTOFF SWITCH OR
FLAME ROLLOUT SAFETY SHUTOFF
SWITCH . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
B. TROUBLESHOOTING GUIDES . . . . . . . . . .32
10. MAINTENANCE 35
A. GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . .36
B. DAILY (WITH BOILER IN USE) . . . . . . . . . . .36
C. WEEKLY (WITH BOILER IN USE) . . . . . . . . .36
D. MONTHLY (WITH BOILER IN USE) . . . . . . .36
E. ANNUALLY (BEFORE START OF HEATING
SEASON) . . . . . . . . . . . . . . . . . . . . . . . . . . .37
11. BOILER DIMENSIONS & RATINGS 38
12. REPAIR PARTS 39
A. BASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
B. GAS MANIFOLD, ORIFICE SPUDS, AND
MAIN BURNERS . . . . . . . . . . . . . . . . . . . . . .40
C. BLOCK AND FLUE COLLECTOR . . . . . . . . .41
D. JACKET . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
E. CONTROLS, DRAFT HOOD AND
AUTOMATIC VENT DAMPER . . . . . . . . . . .43
TABLE OF CONTENTS
TABLE OF CONTENTS

1
A. INSTALLATION SEQUENCE
Follow the installation instructions provided in this
manual in the order shown. The order of these
instructions have been set in order to provide the
installer with a logical sequence of steps that will
minimize potential interferences and maximize safety
during boiler installation.
B. SPECIAL ATTENTION BOXES
Throughout this manual you will see special attention
boxes intended to supplement the instructions and make
special notice of potential hazards. These categories
mean, in the judgment of PB Heat, LLC:
Indicates special attention is needed, but not directly
related to potential personal injury or property
damage.
NOTICE
Indicates a condition or hazard which will or can
cause minor personal injury or property damage.
CAUTION
DANGER
Indicates a condition or hazard which will cause
severe personal injury, death or major property
damage.
USING THIS MANUAL
USING THIS MANUAL
Indicates a condition or hazard which may cause
severe personal injury, death or major property
damage.
WARNING

2
The equipment must be installed in accordance with installation requirements of the authority having
jurisdiction or, in the absence of such requirements, to the current edition of the
National Fuel Gas Code , ANSI
Z223.1/NFPA 54 or CAN/CGA B149 Installation Codes.
Where required by the authority having jurisdiction, the installation must conform to
American Society of
Mechanical Engineers Safety Code for Controls and Safety Devices for Automatically Fired Boilers,
ASME CSD-1.
NOTICE
A. ACCESSIBILITY CLEARANCES
Install boiler with not less than 24" (610 mm) between
the top and front of the boiler and adjacent wall or other
appliance, when access is required for servicing.
B. CLEARANCE FROM COMBUSTIBLE
CONSTRUCTION
The design of this boiler is certified for alcove installation
with the following clearances from combustible
construction:
1. Sides: 6" (152 mm)
2. Top of Jacket: 36" (914 mm)
3. Draft Hood: 6" (152 mm)
4. Vent Pipe: 6" (152 mm )[1" (25 mm) for Type B vent]
5. Rear of Jacket: 6" (152 mm)
6. Hot Water Pipes: 1" (25 mm)
7. If it is necessary to build a non-combustible floor pad
over top of an existing combustible floor, construct
pad as stated in the current edition of National Fuel
Gas Code Handbook under “Installation of Specific
Equipment”, or CAN/CGA B149 Installation Codes
under “General”.
C. COMBUSTION AND VENTILATION AIR
1. Provide adequate facilities for combustion and
ventilation air in accordance with current edition of
National Fuel Gas Code under “Air for Combustion
and Ventilation”, or applicable provisions of the local
building code, or CAN/CGA B149 Installation
Codes. Subsections 2 through 8 below are based on
National Fuel Gas Code requirements.
2. Required Combustion Air Volume: The total required
volume of indoor air is to be the sum of the required
volumes for all appliances located within the space.
Rooms communicating directly with the space in
which the appliances are installed and through
combustion air openings sized as indicated in
Subsection 3 are considered part of the required
volume. The required volume of indoor air is to be
determined by one of two methods.
a. Standard Method: The minimum required
volume of indoor air (room volume) shall be 50
cubic feet per 1000 BTU/Hr (4.8 m3/kW). This
method is to be used if the air infiltration rate is
unknown or if the rate of air infiltration is known
to be greater than 0.6 air changes per hour. As
an option, this method may be used if the air
infiltration rate is known to be between 0.6 and
0.4 air changes per hour. If the air infiltration rate
is known to be below 0.4 then the Known Air
Infiltration Rate Method must be used. If the
building in which this appliance is to be installed
is unusually tight, PB Heat recommends that the
air infiltration rate be determined.
b. Known Air Infiltration Rate Method: Where
the air infiltration rate of a structure is known,
the minimum required volume of indoor air for
appliances other than fan assisted and for the
Series GM Boiler shall be determined as follows:
PREINSTALLATION
1. PREINSTALLATION
Carefully read these instructions before beginning work. Understand all aspects of the installation. Contact your PB Heat sales
representative or customer service for help in answering questions.
This boiler must be installed by a qualified contractor. The boiler warranty can be voided if the boiler is not installed, maintained
and serviced correctly.
Do not install this boiler on combustible flooring.
Boiler installation on combustible flooring is a fire
hazard.
WARNING
Do not install boiler on carpeting. Boiler installation
on carpeting is a fire hazard.
WARNING
21 ft3Iother
ACH 1000Btu/hr
Required Volumeother =⎛
⎜
⎝
⎛
⎜
⎝

3
where:
Iother= Input of appliances other than fan
assisted in Btu/hr
ACH = air change per hour (percent of the
volume of the space exchanged per
hour, expressed as a decimal)
For fan assisted appliances, calculate the required
volume of air using the following equation:
Ifan = Input of the fan assisted appliances in
Btu/hr
Note: These calculations are not to be used for
infiltration rates greater than 0.60 ACH.
3. Indoor Air Opening Size and Location: Openings
connecting indoor spaces shall be sized and located
as follows:
a. Combining spaces on the same floor:
Provide two permanent openings communicating
with additional spaces that have a minimum free
area of 1 in² per 1000 Btu/hr (22 cm² per 1000 W)
of the total input rating of all gas fired equipment
but not less than 100 in² (645 cm²). One
opening is to begin within 12 inches (305 mm)
of the top of the space and the other is to begin
within 12 inches (305 mm) of the floor. The
minimum dimension of either of these openings
shall be 3 inches (76 mm). See Figure 1.1 for an
illustration of this arrangement.
b. Combining spaces on different floors:
Provide one or more permanent openings
communicating with additional spaces that have
a total minimum free area of 2 in² per 1000
Btu/hr (44 cm² per 1000 W) of total input rating
of all equipment. See Figure 1.2 for an
illustration of this arrangement. D.
LIQUEFIED PETROLEUM (LP) GAS
4. Outdoor Combustion Air: Outdoor combustion air is
to be provided through one or two permanent
openings. The minimum dimension of these air
openings is 3 inches (76 mm).
a. Two Permanent Opening Method: Provide
two permanent openings. One opening is to
begin within 12 inches (305 mm) of the top of
the space and the other is to begin within 12
inches (305 mm) of the floor. The openings are
to communicate directly or by ducts with the
outdoors or with spaces that freely communicate
with the outdoors. The size of the openings shall
be determined as follows:
i. Where communicating directly or through
vertical ducts with the outdoors each opening
shall have a minimum free area of 1 in² per
4000 Btu/hr (22 cm² per 4000 W) of total
input rating for all equipment in the space.
See Figure 1.3 for openings directly
communicating with the outdoors or Figure
1.4 for openings connected by ducts to the
outdoors.
PREINSTALLATION
15 ft3Ifan
ACH 1000Btu/hr
Required Volumefan =⎛
⎜
⎝
⎛
⎜
⎝
Figure 1.1: Air Openings – All Air from Indoors
on the Same Floor
Figure 1.2: Air Openings – All Air from Indoors
on Different Floors
Figure 1.3: Air Openings – All Air Directly from
Outdoors

4
ii. Where communicating with the outdoors
through horizontal ducts, each opening shall
have a minimum free area of 1 in² per 2000
Btu/hr (22 cm² per 2000 W) of total rated
input for all appliances in the space. See
Figure 1.5.
b. One Permanent Opening Method: Provide
one permanent opening beginning within 12
inches (305 mm) of the top of the space. The
opening shall communicate directly with the
outdoors, communicate through a vertical or
horizontal duct, or communicate with a space
that freely communicates with the outdoors. The
opening shall have a minimum free area of 1 in²
per 3000 Btu/hr of total rated input for all
appliances in the space and not less than the
sum of the cross-sectional areas of all vent
connectors in the space. The gas-fired equipment
shall have clearances of at least 1 inch (25 mm)
from the sides and back and 6 inches (150 mm)
from the front of the appliance. See Figure 1.6
for this arrangement.
5. Combination Indoor and Outdoor Combustion Air: If
the required volume of indoor air exceeds the
available indoor air volume, outdoor air openings or
ducts may be used to supplement the available
indoor air provided:
a. The size and location of the indoor openings
comply with Subsection 3.
b. The outdoor openings are to be located in
accordance with Subsection 4.
c. The size of the outdoor openings are to be sized
as follows:
where:
Areq = minimum area of outdoor openings.
Afull = full size of outdoor openings calculated
in accordance with Subsection 4.
Vavail = available indoor air volume
Vreq = required indoor air volume
6. Engineered Installations: Engineered combustion air
installations shall provide an adequate supply of
combustion, ventilation, and dilution air and shall be
approved by the authority having jurisdiction.
7. Mechanical Combustion Air Supply:
a. In installations where all combustion air is
provided by a mechanical air supply system, the
combustion air shall be supplied from the
outdoors at the minimum rate of 0.35 ft3/min per
1000 Btu/hr (0.034 m3/min per 1000 W) of the
total rated input of all appliances in the space.
b. In installations where exhaust fans are installed,
additional air shall be provided to replace the
exhaust air. GAS
Figure 1.4: Air Openings – All Air from Outdoors
through Vertical Ducts
Figure 1.5: Air Openings – All Air from Outdoors
through Horizontal Ducts
Figure 1.6: Air Openings – All Air from Outdoors
through One Opening
Vavail
1 – Vreq
Areq = Afull x⎛
⎜
⎝
⎛
⎜
⎝
PREINSTALLATION

5
c. Each of the appliances served shall be
interlocked to the mechanical air supply to
prevent main burner operation when the
mechanical air supply system is not in operation.
d. In buildings where the combustion air is provided
by the mechanical ventilation system, the system
shall provide the specified combustion air rate in
addition to the required ventilation air.
8. Louvers & Grills:
a. The required size of openings for combustion,
ventilation, and dilution air shall be based on the
net free area of each opening.
i. Where the free area through a louver or grille
is known, it shall be used in calculating the
opening size required to provide the free area
specified.
ii. Where the free area through a louver or grille
is not known, it shall be assumed that wooden
louvers will have 25% free area and metal
louvers and grilles will have 75% free area.
iii. Nonmotorized dampers shall be fixed in the
open position.
b. Motorized dampers shall be interlocked with the
equipment so that they are proven in the full
open position prior to ignition and during
operation of the main burner.
i. The interlock shall prevent the main burner
from igniting if the damper fails to open
during burner startup.
ii. The interlock shall shut down the burner if
the damper closes during burner operation.
9. Combustion Air Ducts
a. Ducts shall be constructed of galvanized steel or
an equivalent corrosion- resistant material.
b. Ducts shall terminate in an unobstructed space,
allowing free movement of combustion air to the
appliances.
c. Ducts shall serve a single space.
d. Ducts shall not serve both upper and lower
combustion air openings where both such
openings are used. The separation between ducts
serving upper and lower combustion air
openings shall be maintained to the source of
combustion air.
e. Ducts shall not be screened where terminating in
an attic space.
f. Horizontal upper combustion air ducts shall not
slope downward toward the source of the
combustion air.
g. The remaining space surrounding a chimney
liner, gas vent, special gas vent, or plastic piping
installed within a masonry, metal, or factory built
chimney shall not be used to supply combustion
air.
h. Combustion air intake openings located on the
exterior of buildings shall have the lowest side of
the combustion air intake opening at least 12
inches (305 mm) above grade.
D. INSTALLATION SURVEY
For new and existing installations, a Water Installation
Survey is available from PB Heat. The survey will
provide information on how a hot water boiler works
with your specific system and will provide an overview
of hot water system operation in general.
E. CIRCULATORS
The Series GM boiler is not equipped with a circulator
or a means to control circulator operation. Provide
circulator and zone controls, such as Taco zoning
circulator or Honeywell R845.
F. PLANNING THE LAYOUT
Prepare sketches and notes of the layout to minimize the
possibility of interferences with new or existing
equipment, piping, venting and wiring.
Liquefied Petroleum (LP) is heavier than air and may
collect or “pool” in a low area in the event of a leak
from defective equipment. This gas may then ignite,
resulting in a fire or explosion.
WARNING
PREINSTALLATION

6
BOILER SET-UP
1. Provide a sound, level foundation. Locate boiler as
near to the chimney or outside wall as possible and
centralized with respect to the heating system.
2. Locate boiler in front of installation position before
removing crate.
3. Separate the wood shipping pallet from the boiler
base by removing two (2) hold-down bolts at each
end of the boiler base.
4. Move boiler into final position.
2. BOILER SET-UP

7
Design piping and size circulator(s) to suit the system. Refer to
the I=B=R - Residential Hydronic Heating Installation/Design
Guide and the PB Heat Water Survey for guidance.
A. BOILER SUPPLY AND RETURN
Install boiler to protect the gas ignition system
components from water (dripping, spraying, etc.) during
appliance operation and service (circulator replacement,
condensate trap, control replacements, etc.).
1. Remove shipping nipple from supply tapping.
2. Install temperature-pressure gage with tee in
supply tapping. Nipple, tee, bushing and gage are
located in trim carton. See Figure 3.1.
3. Install drain valve. Remove jacket front panel.
Install drain valve with tee in return tapping. Nipple,
tee, bushing and drain valve are located in trim
carton. See Figure 3.3. Tee may be installed with run
in either horizontal or vertical orientation.
4. Install supply piping, return piping and circulator.
See Figure 3.2.
a. If boiler is installed above radiation level, provide
a low water cutoff device in the supply piping
above boiler. See Figure 3.2.
3. WATER PIPING AND CONTROLS
Figure 3.2: Typical Supply and Return Piping
Figure 3.1: Temperature-Pressure Gage Installation
WATER PIPING AND CONTROLS

8
b. When system return water temperature will be
below 130°F (54°C), pipe the boiler with a
bypass arrangement to blend the system return
and hot supply to obtain at least 130°F (54°C)
entering the boiler. For more information on
bypass piping, consult the PB Heat Water
Installation Survey.
c. If this boiler and distribution system is used in
conjunction with a refrigeration system, pipe the
chilled medium in parallel with the boiler and
install the proper valve to prevent the chilled
medium from entering the boiler. See Figure 3.4.
d. When the boiler is connected to heating coils
located in air handling units where they may be
exposed to refrigerated air circulation, install flow
control valves or other automatic means to
prevent gravity circulation of the boiler water
during the cooling cycle.
B. SAFETY RELIEF VALVE
1. Locate safety relief valve and nipple in trim carton.
2. Install safety relief valve in 3/4 NPT tapping behind
supply tapping. Safety relief valve must be installed
with spindle in vertical position. See Figure 3.5.
Pipe the discharge of safety relief valve to prevent
injury in the event of pressure relief. Pipe the
discharge to a drain. Provide piping that is the same
size as the safety relief valve outlet.
CAUTION
Figure 3.5: Safety Relief Valve Installation
Figure 3.4: Parallel Hook-up with Water Chiller
WATER PIPING AND CONTROLS
Figure 3.3: Drain Valve Installation

9
C. PIPING FOR ZONED SYSTEMS
1. See Figures 3.6 and 3.7 for basic zoned system
layouts. Circulators may be installed in either supply
or return piping. Refer to PB Heat Water Installation
Survey for additional information.
2. Run each zone pipe down then up to zone to
prevent air accumulation in piping.
3. If required, provide means to isolate and drain each
zone separately.
Figure 3.6: Zone Piping with Zone Valves
Figure 3.7: Zone Piping with Circulators
WATER PIPING AND CONTROLS

10
D. EXPANSION TANK
1. Consult the tank manufacturer’s instructions for
specific information relating to tank installation. Size
the expansion tank for the required system volume
and capacity. See Table 11.1 for boiler’s water
content.
2. Expansion tanks are available with built-in fill valves
and check valves for reducing supply water pressure
and maintaining minimum system pressure. Check
the design features of the tank and provide valves as
necessary.
Refer to Figure 3.2 for typical expansion tank piping.
E. INDIRECT-FIRED WATER HEATER
Boiler may be used as heat source for indirect-fired
water heater. Refer to Figure 3.8 for typical piping.
Follow the instructions provided by the water heater
manufacturer. Pipe the water heater as if a separate
space heating zone.
F. FREEZE PROTECTION
For new or existing systems that must be freeze-
protected:
1. Glycol for hydronic applications is specially
formulated with inhibitors which prevent the glycol
from attacking metallic system components. Make
certain that the system fluid is checked for the
correct glycol concentration and inhibitor level.
2. Antifreeze solutions expand more than water. For
example, a 50% by volume solution expands 4.8%
in volume for a temperature increase from 32°F
(0°C) to 180°F (82°C), while water expands 3% with
the same temperature rise. Allowance must be made
for this expansion in system design.
3. For more information, consult the PB Heat Water
Installation Survey and the antifreeze manufacturer.
Figure 3.8: Typical Piping with Indirect-Fired Water Heater
WATER PIPING AND CONTROLS
Use only inhibited propylene glycol solutions of up to
50% by volume with water. Ethylene glycol is toxic
and can attack gaskets and seals used in hydronic
systems.
WARNING

11
A. DRAFT HOOD
1. The boiler is equipped with a draft hood designed to:
a. provide for the ready escape of flue gases from
the boiler in the event of no draft.
b. prevent a backdraft from entering the boiler.
c. control stack draft during operation.
The draft hood must be installed without alteration.
Make certain there are no obstructions to airflow to
the relief opening.
2. Position draft hood with 1" (25 mm) diameter hole in
conical portion of draft hood (for vent safety shutoff
switch) towards front right corner of boiler. Secure to
flue collector with sheet metal screws. See Figure 4.1.
3. The boiler is equipped with a vent safety shutoff
switch. The switch is shipped in a cloth bag attached
to the harness on the exterior of the boiler. Attach
switch to holes in the conical portion of the draft
hood using the screws provided in bag. See
Figure 4.1.
Vent safety shutoff switch wiring harness must extend
to vent safety shutoff switch without excessive slack.
To adjust harness length, squeeze strain relief bushing
to release from jacket. Adjust harness to proper
length. Reinsert strain relief bushing.
4. VENTING
Figure 4.2: Venting Multiple Appliances
VENTING
Figure 4.1: Draft Hood and Vent Safety Shutoff
Switch Installation

12
Figure 4.3: Venting with Vent Damper in Vertical Position
B. AUTOMATIC VENT DAMPER
INSTALLATION – GENERAL
1. Do not use one vent damper to control two or more
heating appliances. See Figure 4.2.
2. Follow these and the installation instructions included
with the vent damper. Observe the cautions and
warnings that accompany all instructions.
3. Provide minimum 6 inch (152 mm) clearance
between automatic vent damper and combustible
construction. Increase clearance if required by vent
damper manufacturer’s instructions. Provide
adequate space for vent damper access and service.
4. The automatic vent damper can be mounted directly
onto the draft hood outlet or in vent piping close to
the boiler.
See Figure 4.3 for installation with vent damper
mounted in vertical position. See Figure 4.4 for
installation with vent damper mounted in horizontal
position. Mount the unit to avoid excessive heat on
the operator or condensation drips into the operator.
a. Orient the vent damper operator to facilitate
connection of the vent damper harness to
knockout on right side of boiler. See Figure 6.1.
b. Orient vent damper direction arrow in direction
of vent gas flow. Direction arrow must be visible
from front of boiler.
C. VENT PIPING AND CHIMNEY
1. Install vent piping in accordance with current edition
of National Fuel Gas Code, ANSI Z223.1/NFPA 54
under “Venting of Equipment”, or applicable
provisions of the local building codes, or CAN/CGA
B149 Installation Codes.
2. Inspect the existing chimney and lining for structural
soundness, corrosion and perforations. Repair as
necessary.
3. Install vent pipe to slope upward at least 1/4" per
lineal foot (21 mm per meter) between the draft
hood outlet and the chimney.
4. Before connection of joints, inspect the vent pipe
interior for foreign objects such as tools, equipment,
rags, etc. and remove if present.
5. Insert vent pipe into but not beyond the inside wall
of the chimney flue.
6. Do not connect vent connectors serving appliances
vented by natural draft into any portion of
mechanical draft systems operating under positive
pressure.
7. Support horizontal portions of the venting system to
prevent sagging by use of metal strapping or
equivalent means. Locate supports at no more than
four (4) foot (122 cm) intervals, or in accordance with
vent system manufacturer’s installation instructions.
VENTING

13
D. BOILER REMOVAL FROM COMMON
VENTING SYSTEM
At the time of removal of an existing boiler, follow these
steps with each appliance remaining connected to the
common venting system placed in operation, while the
other appliances remaining connected to the common
venting system are not in operation:
a. Seal any unused openings in the common venting
system.
b. Visually inspect the venting system for proper size
and horizontal pitch and determine there is no
blockage or restriction, leakage, corrosion and other
deficiencies which could cause an unsafe condition.
c. Insofar as is practical, close all building doors and
windows and all doors between the space in which
the appliances remaining connected to the common
venting system are located and other spaces of the
building. Turn on any clothes dryers and any
appliance not connected to common venting system.
Turn on any exhaust fans, such as range hoods and
bathroom exhausts, so they will operate at maximum
speed. Do not operate a summer exhaust fan. Close
fireplace dampers.
d. Place in operation the appliance being inspected.
Follow the lighting instructions. Adjust thermostat so
appliance will operate continuously.
e. Test for spillage at the draft hood relief opening after
5 minutes of main burner operation. Use the flame
of a match or candle, or smoke from a cigarette,
cigar, or pipe.
f. After it has been determined that each appliance
remaining connected to the common venting system
properly vents when tested as outlined above, return
doors, windows, exhaust fans, fireplace dampers and
any other gas-burning appliance to their previous
conditions of use.
g. Any improper operation of the common venting
system should be corrected so that the installation
conforms with the National Fuel Gas Code, ANSI
Z223.1/NFPA 54 or CAN/CGA B149 Installation
Codes.When resizing any portion of the common
venting system, the common venting system should
be resized to approach minimum size as determined
using the appropriate tables located in the chapter
“Sizing of Category I Venting Systems,” of the
National Fuel Gas Code, ANSI Z223.1/NFPA 54 or
CAN/CGA B149 Installation codes.
VENTING
Figure 4.4: Venting with Vent Damper in Horizontal Position

14
1. Size and install the gas supply piping to provide a
supply of gas sufficient to meet the maximum
demand of all appliances without undue loss of
pressure between the meter and the boiler.
Maximum permissible gas supply pressure to the
boiler is 13.5 inches (3.4 kPa) water column.
2. Determine the volume of gas to be provided to the
boiler. Obtain this value by dividing the Btu per hour
(Watts) rating (on the boiler rating plate) by the
heating value of the gas in Btu per cubic feet (Joules
per cubic meter). Obtain the heating value of the gas
from the gas supplier. As an alternative, use Table
5.1 to obtain the volume of gas to be provided to
the boiler.
3. Table 2 shows the maximum flow capacity of several
pipe sizes based on 0.3" w.c. (.08 kPa) of water
pressure drop. These values are based on a specific
gravity of 0.60. Apply the factors indicated in Table 3
for gas with specific gravity other than 0.60 to obtain
corrected capacities.
4. Connection of boiler to the gas piping system may
be made on the left side or top of the boiler. See
Figure 11.1 for jacket opening locations.
5. Install a sediment trap. See Figure 5.1. Locate a tee
in the drop pipe at same elevation as the gas inlet
connection to the boiler. Extend the drop pipe to a
pipe cap. As an alternate, the sediment trap may be
located in the boiler vestibule. See Figure 5.2.
6. Install a ground joint union ahead of the gas control
assembly to permit servicing of the control. Some
local codes require an additional equipment shutoff
valve when using the combination gas controls. If
your code requires such a valve, a suggested
location is shown in Figure 5.1 or 5.2.
7. Check piping for leaks. Use an approved gas
detector, a non-corrosive leak detection fluid or other
leak detection method. If leaks are found, turn off all
gas flow and repair as necessary.
5. GAS PIPING
Figure 5.1: Gas Connection to Boiler - External
When checking for leaks, do not use matches,
candles, open flames or other methods that provide a
source of ignition. This can ignite a gas leak,
resulting in fire or explosion.
WARNING
Use a pipe joint sealing compound that is resistant to
the action of liquefied petroleum gas. A non-resistant
compound may lose sealing ability in the presence of
this gas, resulting in a gas leak and fire or explosion
potential.
WARNING
GAS PIPING
10
20
30
40
50
60
Pipe
Length
Feet
278
190
152
130
115
105
3/4"
Pipe
520
350
285
245
215
195
1"
Pipe
1,050
730
590
500
440
400
1-1/4"
Pipe
1,600
1,100
890
760
670
610
1-1/2"
Pipe
Capacity of Schedule 40 pipe [cu. ft. per hour (cu. m per
hour)] with pressure drop of 0.3 in. (75 Pa) and specific gravity
of 0.60. No allowance for an ordinary number of fittings is
required.
Table 5.1: Input
Model
Natural Gas LP Gas
(Cubic Feet
Per Hour)
(Cubic Meter
Per Hour)
(Cubic Feet
Per Hour)
(Cubic Meter
Per Hour)
GM-05 228 6.5 91 2.6
GM-06 285 8.1 114 3.2
GM-07 342 9.7 137 3.9
GM-08 399 11.3 160 4.5
Natural gas based on 1000 Btu/Cubic Foot (37,300 kJ/m³).
LP gas based on 2,500 Btu/Cubic Foot (93,145 kJ/m³).
Table 5.2: Capacity of Schedule 40 Pipe
7.8
5.4
4.3
3.7
3.3
3.0
15
9.9
8.1
6.9
6.1
5.5
30
21
17
14
12
11
45
31
25
22
19
17
m³ m³ m³ m³ft.³ ft.³ ft.³ ft.³
Table 5.3: Maximum Capacity Correction Factors
Specific Gravity other than 0.60
Specific Gravity 0.50 0.55 0.60 0.65 0.70 0.75
Correction Factor 1.10 1.04 1.00 0.96 0.93 0.90
Specific Gravity 0.80 0.85 0.90 1.00 1.10 1.20
Correction Factor 0.87 0.84 0.82 0.78 0.74 0.71
Specific Gravity 1.30 1.40 1.50 1.60 1.70 1.80
Correction Factor 0.68 0.66 0.63 0.61 0.59 0.58

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GAS PIPING
8. Disconnect the boiler and its individual shut-off valve
from the gas supply piping system during any
pressure testing of that system at test pressure in
excess of 1/2 psig (3.5 kPa).
Isolate the boiler from the gas supply piping system
by closing its individual service valve during any
pressure testing of the gas supply piping system at
test pressure equal to or less than 1/2 psig (3.5 kPa).
9. Minimum permissible natural gas supply pressure
Inches Water Column (kPa)]:
Minimum permissible LP gas supply pressure is
11.0" w.c. (2.7 kPa).
10. Maximum permissible supply pressure to the boiler
[Inches Water Column (kPa)]:
All models 13.5" (3.4 kPa)
Do not subject the gas valve to more than 1/2 psi
pressure (3.5 kPa). Doing so may damage the valve.
CAUTION
Figure 5.2: Gas Connection to Boiler - Internal
Standing Pilot
Intermittent
Ignition
4.8
4.5
GM-05
5.5
4.5
GM-06 GM-07
----
4.9
GM-08
In. In. In.
----
4.6
In.
1.2
1.1
kPa
1.4
1.1
kPa
----
1.1
kPa
----
1.2
kPa

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A. WIRING
1. See Figure 6.1 for location of wiring and controls.
use Figures 6.4 - 6.6 to connect the boiler to a
power supply and then connect components to the
boiler.
2. Connect the boiler to a separate, permanently live
electrical supply line with a fused switch.
3. Connect the vent damper harness to the polarized
connector in the boiler vestibule as shown in
Figure 6.1.
B. CIRCULATOR/ZONE VALVE WIRING
1. A zone control is required to operate circulator(s)
when using a low voltage thermostat.
2. Taco Zoning circulator(s) can be used instead of
mounting separate circulator relay(s) (Figure 6.2).
3. Figure 6.8 shows typical wiring for one or more
circulators.
4. Figure 6.9 shows typical wiring for zone valves.
C. LOW WATER CUTOFF
Wire low water cutoff to turn off power to boiler. See
Figure 6.3 for Hydrolevel 550 low water cutoff. Refer to
manufacturer’s instructions for other low water cutoffs.
ELECTRICAL
6. ELECTRICAL
This unit when installed must be electrically grounded in accordance with the requirements of the authority
having jurisdiction or, in the absence of such requirements, with the current edition of the
National Electrical
Code
, ANSI/NFPA 70 or the Canadian Electrical Code Part I, CSA C22.1, Electrical Code.
NOTICE
Figure 6.1: Wiring Details
Do not power zone valves directly from the boiler
transformer. Doing so will greatly reduce the life of
the transformer. Use a separate transformer sized to
handle the total of all zone valve electrical loads.
NOTICE

17
Figure 6.2: Taco Zoning Circulator Wiring
ELECTRICAL
Figure 6.3: Hydrolevel 550 Low Water Cutoff Wiring

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ELECTRICAL
SEQUENCE OF OPERATION, INTERMITTENT
IGNITION:
1. Thermostat calls for heat.
2. Limit senses boiler water temperature. Prevents
operation until water temperature falls approximately
15°F (9°C) below the cut-out temperature.
3. Automatic vent damper (if used) opens. Damper
must be in open position when appliance main
burner(s) is operating.
4. Gas valve energizes.
a. Igniter on.
b. Pilot gas on, igniting pilot.
5. Pilot flame detected.
a. Igniter off.
b. Main gas on, igniting main burners.
Note: If pilot flame is not detected within 30 seconds,
the igniter is turned off for 30 seconds, and then turned
back on. If the pilot is not detected within 30 seconds,
the igniter and pilot gas are turned off for 5 minutes.
The sequence then resumes at Step 4a.
6. Call for heat ends.
a. Pilot and main gas off, extinguishing pilot and
main burners.
b. Automatic vent damper (if used) closes.
Figure 6.4: Connection and Schematic Diagram, Intermittent Ignition, Natural Gas